Every day, we use paper in many fields, such as office print, academic documents, and legal documents, which are often used for contracts and legal documents. But in many cases, we don’t know which one is the standard paper size for our project. We often waste materials, raise costs, and add complexity using the wrong paper size. 

So, in this article, we discuss about standard paper size and its uses. Let’s begin:

Table Of Contents

  1. What is Standard Paper Size?
  2. A-Series – The International Standard paper size
  3. B-Series – For Larger Formats
  4. C-Series paper size:
  5. North American Standard paper size
  6. R-Series: The Standard Paper Size
  7. ANSI Series: Architectural standard paper size
  8. ARCH Series: The Architectural Connection
  9. Other common Standard Paper Size
  10. How to Choose the Right Paper Size?

What is Standard Paper Size?

Standard paper sizes are sets of predefined dimensions for paper sheets that are widely used and recognized in a particular region or internationally. The 8.5 × 11-inch is an internationally popular standard paper size format. Standard paper sizes also facilitate consistency in daily printing, document production, and manufacturing related products like envelopes and binders. 

There are two main systems of standard paper sizes:

  1. International Standards (ISO 216): International standards ISO 216 uses a matrix system. It is the most widely used globally. It includes the A-series, B-series, and C-series. Each is designed for a specific purpose.
  2. North American Standards: People in the United States and Canada use North American standard paper. It includes Letter, Legal, and Tabloid sizes.

Each system offers a range of sizes to accommodate various needs, from everyday printing and writing to large-format posters and newspapers. Standard paper sizes simplify the process of selecting paper, designing documents, and ensuring compatibility with printers and other equipment.

A-Series – The International Standard paper size

The A-series is most popular internationally. Originating from the German DIN 476 standard and now adopted globally as ISO 216, the A-series boasts a unique aspect ratio of about 1:1.414 and practical dimensions, making it the go-to choice for various applications worldwide.

One of the most important secrets of an A Series is that when you fold an A-size sheet half widthwise, you get two perfect sheets of the next smaller A-size. This unique property allows for easy scaling and efficient use of paper.

Common Uses of A-Series Paper:

  • A4 (210 x 297 mm): This size is common for letter paper and documents in most countries outside North America. It’s ideal for letters, reports, and everyday printing.
  • A3 (297 x 420 mm): It’s twice the size of A4. A3 is great for posters, charts, and diagrams. It’s also a popular choice for folding into A4 booklets.
  • A5 (148 x 210 mm): A5 paper is half the size of A4. It’s often used for notebooks, notepads, and small documents. It’s also a standard size for pocketbooks and booklets.
  • Smaller A-sizes (A6, A7.): These compact sizes are perfect for postcards, pocket notebooks, and notepads. They’re often used for quick notes and reminders.

Standard paper sizes: A-series in inches, cm, mm.

A Size Inches CM MM
A0 33.1 x 46.8 84.1 x 118.9 841 x 1189
A1 23.4 x 33.1 59.4 x 84.1 594 x 841
A2 16.5 x 23.4 42.0 x 59.4 420 x 594
A3 11.7 x 16.5 29.7 x 42.0 297 x 420
A4 8.27 x 11.7 21.0 x 29.7 210 x 297
A5 5.83 x 8.27 14.8 x 21.0 148 x 210
A6 4.13 x 5.83 10.5 x 14.8 105 x 148
A7 2.91 x 4.13 7.4 x 10.5 74 x 105
A8 2.05 x 2.91 5.2 x 7.4 52 x 74
A9 1.46 x 2.05 3.7 x 5.2 37 x 52
A10 1.02 x 1.46 2.6 x 3.7 26 x 37

Whether you’re writing a letter, designing a poster, or putting down a quick note, the A-series has a size to fit your needs. Its standardized dimensions and consistent aspect ratio make it a truly global standard, promoting efficiency and ease of use in a world of diverse paper needs.

B-Series – For Larger Formats

let’s talk about B series paper sizes. We have discussed about A4 size, The standard paper size for most of our schoolwork. But did you know another set of paper sizes called the B-series? B series is not commonly used, but they have special uses in many projects. Let’s explore the use of the B series.

What are B-Sizes Used For?

B-sizes are great for certain projects that are given:

  • B5: B5 paper sizes are mainly used in books, smaller notebooks, and posters that you see at the store. They’re often B5 size. This size is also great for flyers, handouts, and even brochures.
  • B4: This is the size of many magazines, reports you might have to write for school, and even some music sheets. It’s a versatile size that’s bigger than A4 but not as large as B3.
  • B3: If you’ve ever seen a big poster on the wall, it might be a B3. This size is perfect for attention-grabbing displays, wall charts, or even large artwork. Some calendars and maps are also printed on B3.

Why Don’t We See B-Sizes Everywhere?

  • A-sizes are the superstars: They’re the most popular and used for almost everything.
  • Many options: A-sizes come in many different sizes, so you usually find one that fits your needs.
  • Tricky cutting: A-sizes are easy to cut in half, and you get another A-size. B-sizes don’t have this cool feature.

B-series in inches, cm, mm.

B Size Inches CM MM
B0 39.37 x 55.67 100 x 141.4 1000 x 1414
B1 27.83 x 39.37 70.7 x 100 707 x 1000
B2 19.69 x 27.83 50 x 70.7 500 x 707
B3 13.90 x 19.69 35.3 x 50 353 x 500
B4 9.84 x 13.90 25 x 35.3 250 x 353
B5 6.93 x 9.84 17.6 x 25 176 x 250
B6 4.92 x 6.93 12.5 x 17.6 125 x 176
B7 3.46 x 4.92 8.8 x 12.5 88 x 125
B8 2.44 x 3.46 6.2 x 8.8 62 x 88
B9 1.73 x 2.44 4.4 x 6.2 44 x 62
B10 1.22 x 1.73 3.1 x 4.4 31 x 44

C-Series paper size: 

We’ve talked about A-sizes for printing and B-sizes for posters and books. But, there’s another set of paper sizes hiding in plain sight – the C-series. You might not see them labeled on a piece of paper, but you use them every day without even realizing it. Let’s solve the mystery of these special paper sizes. We’ll discover why they’re essential for keeping your letters and documents safe.

The C-series has one very important job. It makes envelopes. This is unlike the A-series and the B-series. Every envelope you’ve ever used was probably a C-size.

The C-size is actually a bit bigger than the A-size. This extra space is crucial. It lets you easily slide the paper in and out of the envelope. You can do this without bending or damaging it.

Let’s explore the common C series paper size:

  • C4: The most common envelope you’ll find. It’s perfect for your standard A4 papers. It’s for a handwritten or printed document.
  • C5: If you fold an A4 sheet in half, a C5 envelope is your go-to. It also snugly fits unfolded A5 papers.
  • C6: This smaller size is ideal for postcards, folded A4 sheets, or those little A6 cards.

C-series in inches, cm, mm.

C Size Inches CM MM
C0 43.27 x 61.38 109.9 x 156 1099 x 1560
C1 30.63 x 43.27 77.8 x 109.9 778 x 1099
C2 21.65 x 30.63 55 x 77.8 550 x 778
C3 15.32 x 21.65 38.9 x 55 389 x 550
C4 10.83 x 15.32 27.5 x 38.9 275 x 389
C5 7.66 x 10.83 19.5 x 27.5 195 x 275
C6 5.41 x 7.66 13.7 x 19.5 137 x 195
C7 3.83 x 5.41 9.7 x 13.7 97 x 137
C8 2.70 x 3.83 6.9 x 9.7 69 x 97
C9 1.91 x 2.70 4.9 x 6.9 49 x 69
C10 1.35 x 1.91 3.4 x 4.9 34 x 49

Why are C-sizes important?

Using c series, Your papers stay safe from folds, creases, and tears when they have a C-size envelope as their bodyguard. Don’t have to find different envelopes to find the right fit. With C series, you can do everything. Using a matching envelope and paper size gives your letters and documents a polished look. 

You’ll find C-size envelopes everywhere. Like birthday cards, bills, and official documents, The C-series is working hard behind the scenes to keep our communication organized and safe.

North American Standard paper size

We’ve learned through the A, B, and C series of the international ISO standard paper sizes. Now, let’s explore the paper sizes you’ll find in North America. Get ready for a slight change of pace – and size.

US Letter size

In North America, the standard paper size isn’t A4. It’s actually US Letter size . It’s 8.5 by 11 inches. This size is common for documents, letters, schoolwork, and daily printing. You’ll find US letters used in everything from printer paper to magazines to notebooks.

The North American Paper size

The US Letter isn’t the only one in the North American paper world. There are a few other common sizes with their own unique uses:

  • Legal: This longer sheet (8.5 x 14 inches) is commonly used for legal documents, contracts, and forms. Its extra length provides space for detailed information and signatures.
  • Tabloid/Ledger: Double the size of a US Letter (11 x 17 inches); this larger format is used for newspapers, spreadsheets, accounting ledgers, and posters. It’s also a popular choice for creating brochures and flyers.

North American Paper Sizes in inches, cm, mm.

Size Name Inches CM MM
Letter 8.5 x 11 21.59 x 27.94 216 x 279
Legal 8.5 x 14 21.59 x 35.56 216 x 356
Tabloid/Ledger 11 x 17 27.94 x 43.18 279 x 432
Government Letter 8 x 10 20.32 x 25.4 203 x 254
Junior Legal 8 x 5 20.32 x 12.7 203 x 127
Statement/Half Letter 5.5 x 8.5 13.97 x 21.59 140 x 216

Why Different Sizes?

You might wonder why North America has different paper sizes than other countries. These sizes have roots in early papermaking practices and traditions unique to North America. They might not align with international standards. But they’ve become deeply ingrained in everyday life.

You’re writing a letter, reading a newspaper, or filling out a form. You’re interacting with the world of paper sizes. The international A-series has different sizes than the North American standards. Each size has its own story and purpose. By understanding these differences, you can confidently navigate the world of paper size.

R-Series: The Standard Paper Size

R series originated in Japan. This system has become the go-to for photographs across Asia and is gaining popularity worldwide. But there’s more to this story than just your standard paper size.

The R-series focuses on ratios. These sizes have a 2:3 aspect ratio. This means the width is two-thirds of the height. This ratio creates pleasing proportions. R-series paper is popular for everyday photos. They are also popular for portraits and event photos.

Common R-Sizes and Their Uses

  • 4R (4×6 inches): The most popular size for standard prints. Perfect for photo albums, wallets, or small frames.
  • 5R (5×7 inches): A step up from 4R, it’s often used for framing and gifts. Also great for creating personalized greeting cards or invitations.
  • 6R (6×8 inches): 6R is Ideal for landscape photos or group shots, and it’s also popular for larger frames or photo books.
  • 8R (8×10 inches): 8R is Commonly used for portraits, wall displays, or making a statement in a photo album. This size is also popular for printing artwork or illustrations.
  • 10R (10×12 inches): It is Perfect for creating large, eye-catching wall art or stunning photo collages. It’s also a great choice for creating calendars or custom posters.

R-series in inches, cm, mm.

R Size Inches CM MM
2R 2.5 x 3.5 6.35 x 8.89 63.5 x 88.9
3R 3.5 x 5 8.89 x 12.7 88.9 x 127
4R 4 x 6 10.16 x 15.24 101.6 x 152.4
5R 5 x 7 12.7 x 17.78 127 x 177.8
6R 6 x 8 15.24 x 20.32 152.4 x 203.2
8R 8 x 10 20.32 x 25.4 203.2 x 254
10R 10 x 12 25.4 x 30.48 254 x 304.8

Where to Find R-Series Prints

R-series prints are readily available at most photo labs, online printing services, and even some retail stores. Just ask for the specific R-size you need, 

RA and SRA Series: Behind the Scenes

But the R-series doesn’t stop there! There are two additional series that play important roles in the printing process:

  • RA Series: These sizes are slightly larger than their corresponding R-sizes, providing extra space for printing borders, bleeds, or trimming. They’re like the “rough draft” of your final print, giving you room for adjustments.

All RA-series in inches, cm, and mm.

Size Name Inches CM MM
RA0 33.86 x 47.64 86 x 121 860 x 1210
RA1 23.78 x 33.86 60.5 x 86 605 x 860
RA2 16.77 x 23.78 42.6 x 60.5 426 x 605
RA3 11.89 x 16.77 30.2 x 42.6 302 x 426
RA4 8.46 x 11.89 21.5 x 30.2 215 x 302
  • SRA Series: Similar to the B-series, the SRA series offers sizes between the standard R-sizes. This allows for more flexibility when printing and binding. It is especially useful for booklets, brochures, and magazines.

SRA-series in inches, cm, mm.

SRA Size Inches CM MM
SRA0 36.02 x 50.39 91.5 x 128 915 x 1280
SRA1 25.40 x 36.02 64.5 x 91.5 645 x 915
SRA2 17.99 x 25.40 45.7 x 64.5 457 x 645
SRA3 12.70 x 17.99 32.3 x 45.7 323 x 457
SRA4 9.00 x 12.70 22.9 x 32.3 229 x 323

The R-series offers a standardized system for printing photos aesthetically, ensuring your pictures look their best. But it’s not just about the final product; the RA and SRA series play an essential role in the printing process, allowing for creativity and flexibility.

The R–series is not just a size. It’s a standard paper size for capturing and preserving your precious moments. And don’t forget about the RA and SRA series, which make the printing process smoother.

ANSI Series: Architectural standard paper size 

You might not know this, but you’ve probably seen the power of the ANSI series. These are super big pieces of paper used to make drawings of buildings and other cool things. It’s the backbone of technical and architectural designs. Let’s learn more about these special papers.

Introducing the ANSI A-E Series:

A4 and Letter sizes are common in offices and homes. However, the ANSI series is for large-scale design. It includes sizes A (8.5″ x 11″), B (11″ x 17″), C (17″ x 22″), D (22″ x 34″), and E (34″ x 44″). Each size has a unique design purpose.

  • ANSI A (8.5″ x 11″): It’s used to reduce size when printing larger drawings, making them easier to handle and share. Also ideal for detailed sections or components within a larger plan.
  • ANSI B (11″ x 17″): Well-suited for diagrams, flowcharts, and initial sketches. It provides more space than letter-sized paper. This is for brainstorming and early design drafts.
  • ANSI C (17″ x 22″) is a common size for architectural drawings. It’s perfect for floor plans and elevations, balancing detail and ease of use.
  • ANSI D (22″ x 34″) is ideal for large, complex plans. It suits detailed mechanical drawings or electrical schematics. Also, it shows intricate details and annotations clearly.
  • ANSI E (34″ x 44″): ANSI E (34″ x 44″) sheets are for large projects. These include site plans, engineering drawings, and presentations. Their size allows a bird’s-eye view of complex systems.

ANSI series In Inches, Cm, mm.

ANSI Size Inches CM MM
ANSI A 8.5 x 11 21.59 x 27.94 215.9 x 279.4
ANSI B 11 x 17 27.94 x 43.18 279.4 x 431.8
ANSI C 17 x 22 43.18 x 55.88 431.8 x 558.8
ANSI D 22 x 34 55.88 x 86.36 558.8 x 863.6
ANSI E 34 x 44 86.36 x 111.76 863.6 x 1117.6

ARCH Series: The Architectural Connection

Architects have their own specialized version of the ANSI series: the ARCH series. ARCH sizes closely mirror ANSI dimensions but often feature slightly adjusted aspect ratios tailored for architectural drawings.

  • ARCHA (9″ x 12″): Similar to ANSI A, used for smaller-scale drawings or details.
  • ARCHB (12″ x 18″): Equal to ANSI B, ideal for preliminary drawings and graphs.
  • ARCHC (18″ x 24″) is a staple in architectural offices. It fits floor plans, elevations, and sections. It also has much space for notes and details.
  • ARCH D (24″ x 36″) is used for larger, detailed architectural plans. It is often for presentations or detailed design.
  • ARCH E (36″ x 48″) is reserved for the most detailed architectural drawings. These include site plans and detailed building sections.

ARCH-series In Inches, Cm, mm.

Size Name Inches  CM  MM
ARCH A 9 x 12 22.86 x 30.48 229 x 305
ARCH B 12 x 18 30.48 x 45.72 305 x 457
ARCH C 18 x 24 45.72 x 60.96 457 x 610
ARCH D 24 x 36 60.96 x 91.44 610 x 914
ARCH E 36 x 48 91.44 x 121.92 914 x 1219
ARCH E1 30 x 42 76.2 x 106.68 762 x 1067

The flexibility of ANSI and ARCH sizes is a major advantage, facilitating seamless collaboration between architects and engineers.

Who uses the ANSI Series?

They heavily rely on the ANSI series. This includes engineers, architects, drafters, product designers, and builders. It’s the foundation for intricate designs. They are used for bridges, factories, airplanes, and many other creations.

Other common Standard Paper Size

Letter (8.5″ x 11″) and A4 (210mm x 297mm) are the standard paper sizes that dominate our lives. However, many other paper formats exist, each with unique purposes. From formal letters to quick notes, these sizes offer flexibility and creativity for various communication needs.

Executive Size (7.25″ x 10.5″):

It’s shorter than the standard letter size, but it’s a perfect choice for: 

  • Formal Letters and Invitations: Make a lasting impression. Use cover letters, thank-you notes, or official invitations. The smaller size adds a sense of exclusivity and personal touch. Imagine a handwritten note on elegant executive stationery.
  • Memos and Reports: Condense information into a neat and concise format for internal communications. The executive size makes memos easier to handle, perfect for leaving a brief message on a colleague’s desk.
  • Certificates and Awards: Best for awards, diplomas, and certificates with an added level of prestige using this format. Think of a framed achievement on executive-sized paper displayed proudly in an office.

Government Letter (8″ x 10″):

The Bureaucratic Workhorse

This size is the backbone of official communication within US government agencies. Slightly shorter and wider than standard letter paper, it offers several practical advantages:

  • Official Documents and Forms: Legal forms, government reports, and various official documents are often printed on government letter size due to their standardization. Use in tax forms or immigration applications.
  • Efficient Filing and Storage: The slightly reduced dimensions make it easier to store and organize large volumes of paperwork in standard filing cabinets.
  • Historical Significance: Government letter size has a long history in US bureaucracy, dating back to the late 19th century when typewriters were widely adopted.

Index Card Sizes:

Index cards, available in various small sizes, it is indispensable tools for organization, note-taking, and creative expression. The most common dimensions are:

  • 3 x 5″: The classic index card size, perfect for quick notes, flashcards, recipe cards, and brainstorming sessions. 
  • 4 x 6″: A larger version offering more space for detailed notes, sketches, or small projects. This size is popular for artists who trade cards or create small collages.
  • 5 x 8″: Even larger, suitable for creating study guides, outlines, or mini-presentations. 

Index cards are also popular among artists and crafters for creating small-scale artworks, journaling, and scrapbooking.

Other common paper sizes: inches, cm, and mm. 

Size Name Inches  CM MM
Executive 7.25 x 10.5 18.42 x 26.67 184 x 267
Government Letter 8 x 10 20.32 x 25.4 203 x 254
Legal 8.5 x 14 21.59 x 35.56 216 x 356
Junior Legal 8 x 5 20.32 x 12.7 203 x 127
Ledger/Tabloid 11 x 17 27.94 x 43.18 279 x 432
Statement/Half Letter 5.5 x 8.5 13.97 x 21.59 140 x 216
Index Card (3×5) 3 x 5 7.62 x 12.7 76 x 127
Index Card (4×6) 4 x 6 10.16 x 15.24 102 x 152
Index Card (5×8) 5 x 8 12.7 x 20.32 127 x 203

How to Choose the Right Paper Size?

Selecting the ideal paper size is a multi-faceted decision. Here’s a structured approach to help you navigate the choices:

Define Your Document Type:

    • Letters, Memos, Invitations: Consider executive size (7.25″ x 10.5″) for a formal touch.
    • Resumes, Certificates, Awards: Executive size is also ideal for professional documents.
    • Flyers, Brochures, Handouts: Opt for tabloid/ledger (11″ x 17″) to accommodate more content and visuals.
    • Posters, Charts, Blueprints: Explore large format options (if your printer allows) or consider professional printing services.
    • Invoices, Receipts, Small Documents: Statement/half letter (5.5″ x 8.5″) is a practical choice.
    • Photos: Choose standard photo sizes based on your desired print dimensions.

Clarify Your Purpose:

      • Informational: Standard letter or A4 sizes are often sufficient.
      • Persuasive: Larger formats can be more impactful for marketing materials.
      • Creative Expression: Explore unique sizes and specialty papers to unleash your imagination.

Check Printer Compatibility:

    • Standard Printer: Ensure your chosen size is supported.
    • Large Format Printer: Explore possibilities beyond standard sizes.

Consider Aesthetics:

    • Classic: Stick with traditional sizes for a timeless feel.
    • Modern: Embrace larger formats or unique shapes for a contemporary look.
    • Personalized: Explore custom sizes or specialty papers for a one-of-a-kind creation.


The standard paper size can lift your message. It can help readability and leave a lasting impression. Consider your document type, purpose, printing limits, and desired look. Then, you can unlock the paper’s full potential as a tool for communication. So, explore the world of standard paper sizes and find the perfect fit for your next project.